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1da177e4 LT |
1 | /* |
2 | * arch/ppc/kernel/ptrace.c | |
3 | * | |
4 | * PowerPC version | |
5 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
6 | * | |
7 | * Derived from "arch/m68k/kernel/ptrace.c" | |
8 | * Copyright (C) 1994 by Hamish Macdonald | |
9 | * Taken from linux/kernel/ptrace.c and modified for M680x0. | |
10 | * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds | |
11 | * | |
12 | * Modified by Cort Dougan (cort@hq.fsmlabs.com) | |
13 | * and Paul Mackerras (paulus@linuxcare.com.au). | |
14 | * | |
15 | * This file is subject to the terms and conditions of the GNU General | |
16 | * Public License. See the file README.legal in the main directory of | |
17 | * this archive for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/kernel.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/smp.h> | |
24 | #include <linux/smp_lock.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/ptrace.h> | |
27 | #include <linux/user.h> | |
28 | #include <linux/security.h> | |
7ed20e1a | 29 | #include <linux/signal.h> |
1da177e4 LT |
30 | |
31 | #include <asm/uaccess.h> | |
32 | #include <asm/page.h> | |
33 | #include <asm/pgtable.h> | |
34 | #include <asm/system.h> | |
35 | ||
36 | /* | |
37 | * Set of msr bits that gdb can change on behalf of a process. | |
38 | */ | |
39 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
40 | #define MSR_DEBUGCHANGE 0 | |
41 | #else | |
42 | #define MSR_DEBUGCHANGE (MSR_SE | MSR_BE) | |
43 | #endif | |
44 | ||
45 | /* | |
46 | * does not yet catch signals sent when the child dies. | |
47 | * in exit.c or in signal.c. | |
48 | */ | |
49 | ||
50 | /* | |
51 | * Get contents of register REGNO in task TASK. | |
52 | */ | |
53 | static inline unsigned long get_reg(struct task_struct *task, int regno) | |
54 | { | |
55 | if (regno < sizeof(struct pt_regs) / sizeof(unsigned long) | |
56 | && task->thread.regs != NULL) | |
57 | return ((unsigned long *)task->thread.regs)[regno]; | |
58 | return (0); | |
59 | } | |
60 | ||
61 | /* | |
62 | * Write contents of register REGNO in task TASK. | |
63 | */ | |
64 | static inline int put_reg(struct task_struct *task, int regno, | |
65 | unsigned long data) | |
66 | { | |
67 | if (regno <= PT_MQ && task->thread.regs != NULL) { | |
68 | if (regno == PT_MSR) | |
69 | data = (data & MSR_DEBUGCHANGE) | |
70 | | (task->thread.regs->msr & ~MSR_DEBUGCHANGE); | |
71 | ((unsigned long *)task->thread.regs)[regno] = data; | |
72 | return 0; | |
73 | } | |
74 | return -EIO; | |
75 | } | |
76 | ||
77 | #ifdef CONFIG_ALTIVEC | |
78 | /* | |
79 | * Get contents of AltiVec register state in task TASK | |
80 | */ | |
81 | static inline int get_vrregs(unsigned long __user *data, struct task_struct *task) | |
82 | { | |
83 | int i, j; | |
84 | ||
85 | if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long))) | |
86 | return -EFAULT; | |
87 | ||
88 | /* copy AltiVec registers VR[0] .. VR[31] */ | |
89 | for (i = 0; i < 32; i++) | |
90 | for (j = 0; j < 4; j++, data++) | |
91 | if (__put_user(task->thread.vr[i].u[j], data)) | |
92 | return -EFAULT; | |
93 | ||
94 | /* copy VSCR */ | |
95 | for (i = 0; i < 4; i++, data++) | |
96 | if (__put_user(task->thread.vscr.u[i], data)) | |
97 | return -EFAULT; | |
98 | ||
99 | /* copy VRSAVE */ | |
100 | if (__put_user(task->thread.vrsave, data)) | |
101 | return -EFAULT; | |
102 | ||
103 | return 0; | |
104 | } | |
105 | ||
106 | /* | |
107 | * Write contents of AltiVec register state into task TASK. | |
108 | */ | |
109 | static inline int set_vrregs(struct task_struct *task, unsigned long __user *data) | |
110 | { | |
111 | int i, j; | |
112 | ||
113 | if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long))) | |
114 | return -EFAULT; | |
115 | ||
116 | /* copy AltiVec registers VR[0] .. VR[31] */ | |
117 | for (i = 0; i < 32; i++) | |
118 | for (j = 0; j < 4; j++, data++) | |
119 | if (__get_user(task->thread.vr[i].u[j], data)) | |
120 | return -EFAULT; | |
121 | ||
122 | /* copy VSCR */ | |
123 | for (i = 0; i < 4; i++, data++) | |
124 | if (__get_user(task->thread.vscr.u[i], data)) | |
125 | return -EFAULT; | |
126 | ||
127 | /* copy VRSAVE */ | |
128 | if (__get_user(task->thread.vrsave, data)) | |
129 | return -EFAULT; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | #endif | |
134 | ||
135 | #ifdef CONFIG_SPE | |
136 | ||
137 | /* | |
138 | * For get_evrregs/set_evrregs functions 'data' has the following layout: | |
139 | * | |
140 | * struct { | |
141 | * u32 evr[32]; | |
142 | * u64 acc; | |
143 | * u32 spefscr; | |
144 | * } | |
145 | */ | |
146 | ||
147 | /* | |
148 | * Get contents of SPE register state in task TASK. | |
149 | */ | |
150 | static inline int get_evrregs(unsigned long *data, struct task_struct *task) | |
151 | { | |
152 | int i; | |
153 | ||
154 | if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long))) | |
155 | return -EFAULT; | |
156 | ||
157 | /* copy SPEFSCR */ | |
158 | if (__put_user(task->thread.spefscr, &data[34])) | |
159 | return -EFAULT; | |
160 | ||
161 | /* copy SPE registers EVR[0] .. EVR[31] */ | |
162 | for (i = 0; i < 32; i++, data++) | |
163 | if (__put_user(task->thread.evr[i], data)) | |
164 | return -EFAULT; | |
165 | ||
166 | /* copy ACC */ | |
167 | if (__put_user64(task->thread.acc, (unsigned long long *)data)) | |
168 | return -EFAULT; | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Write contents of SPE register state into task TASK. | |
175 | */ | |
176 | static inline int set_evrregs(struct task_struct *task, unsigned long *data) | |
177 | { | |
178 | int i; | |
179 | ||
180 | if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long))) | |
181 | return -EFAULT; | |
182 | ||
183 | /* copy SPEFSCR */ | |
184 | if (__get_user(task->thread.spefscr, &data[34])) | |
185 | return -EFAULT; | |
186 | ||
187 | /* copy SPE registers EVR[0] .. EVR[31] */ | |
188 | for (i = 0; i < 32; i++, data++) | |
189 | if (__get_user(task->thread.evr[i], data)) | |
190 | return -EFAULT; | |
191 | /* copy ACC */ | |
192 | if (__get_user64(task->thread.acc, (unsigned long long*)data)) | |
193 | return -EFAULT; | |
194 | ||
195 | return 0; | |
196 | } | |
197 | #endif /* CONFIG_SPE */ | |
198 | ||
199 | static inline void | |
200 | set_single_step(struct task_struct *task) | |
201 | { | |
202 | struct pt_regs *regs = task->thread.regs; | |
203 | ||
204 | if (regs != NULL) { | |
205 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
206 | task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC; | |
207 | regs->msr |= MSR_DE; | |
208 | #else | |
209 | regs->msr |= MSR_SE; | |
210 | #endif | |
211 | } | |
212 | } | |
213 | ||
214 | static inline void | |
215 | clear_single_step(struct task_struct *task) | |
216 | { | |
217 | struct pt_regs *regs = task->thread.regs; | |
218 | ||
219 | if (regs != NULL) { | |
220 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
221 | task->thread.dbcr0 = 0; | |
222 | regs->msr &= ~MSR_DE; | |
223 | #else | |
224 | regs->msr &= ~MSR_SE; | |
225 | #endif | |
226 | } | |
227 | } | |
228 | ||
229 | /* | |
230 | * Called by kernel/ptrace.c when detaching.. | |
231 | * | |
232 | * Make sure single step bits etc are not set. | |
233 | */ | |
234 | void ptrace_disable(struct task_struct *child) | |
235 | { | |
236 | /* make sure the single step bit is not set. */ | |
237 | clear_single_step(child); | |
238 | } | |
239 | ||
240 | int sys_ptrace(long request, long pid, long addr, long data) | |
241 | { | |
242 | struct task_struct *child; | |
243 | int ret = -EPERM; | |
244 | ||
245 | lock_kernel(); | |
246 | if (request == PTRACE_TRACEME) { | |
247 | /* are we already being traced? */ | |
248 | if (current->ptrace & PT_PTRACED) | |
249 | goto out; | |
250 | ret = security_ptrace(current->parent, current); | |
251 | if (ret) | |
252 | goto out; | |
253 | /* set the ptrace bit in the process flags. */ | |
254 | current->ptrace |= PT_PTRACED; | |
255 | ret = 0; | |
256 | goto out; | |
257 | } | |
258 | ret = -ESRCH; | |
259 | read_lock(&tasklist_lock); | |
260 | child = find_task_by_pid(pid); | |
261 | if (child) | |
262 | get_task_struct(child); | |
263 | read_unlock(&tasklist_lock); | |
264 | if (!child) | |
265 | goto out; | |
266 | ||
267 | ret = -EPERM; | |
268 | if (pid == 1) /* you may not mess with init */ | |
269 | goto out_tsk; | |
270 | ||
271 | if (request == PTRACE_ATTACH) { | |
272 | ret = ptrace_attach(child); | |
273 | goto out_tsk; | |
274 | } | |
275 | ||
276 | ret = ptrace_check_attach(child, request == PTRACE_KILL); | |
277 | if (ret < 0) | |
278 | goto out_tsk; | |
279 | ||
280 | switch (request) { | |
281 | /* when I and D space are separate, these will need to be fixed. */ | |
282 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
283 | case PTRACE_PEEKDATA: { | |
284 | unsigned long tmp; | |
285 | int copied; | |
286 | ||
287 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); | |
288 | ret = -EIO; | |
289 | if (copied != sizeof(tmp)) | |
290 | break; | |
291 | ret = put_user(tmp,(unsigned long __user *) data); | |
292 | break; | |
293 | } | |
294 | ||
295 | /* read the word at location addr in the USER area. */ | |
296 | /* XXX this will need fixing for 64-bit */ | |
297 | case PTRACE_PEEKUSR: { | |
298 | unsigned long index, tmp; | |
299 | ||
300 | ret = -EIO; | |
301 | /* convert to index and check */ | |
302 | index = (unsigned long) addr >> 2; | |
303 | if ((addr & 3) || index > PT_FPSCR | |
304 | || child->thread.regs == NULL) | |
305 | break; | |
306 | ||
307 | CHECK_FULL_REGS(child->thread.regs); | |
308 | if (index < PT_FPR0) { | |
309 | tmp = get_reg(child, (int) index); | |
310 | } else { | |
311 | preempt_disable(); | |
312 | if (child->thread.regs->msr & MSR_FP) | |
313 | giveup_fpu(child); | |
314 | preempt_enable(); | |
315 | tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0]; | |
316 | } | |
317 | ret = put_user(tmp,(unsigned long __user *) data); | |
318 | break; | |
319 | } | |
320 | ||
321 | /* If I and D space are separate, this will have to be fixed. */ | |
322 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
323 | case PTRACE_POKEDATA: | |
324 | ret = 0; | |
325 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) | |
326 | break; | |
327 | ret = -EIO; | |
328 | break; | |
329 | ||
330 | /* write the word at location addr in the USER area */ | |
331 | case PTRACE_POKEUSR: { | |
332 | unsigned long index; | |
333 | ||
334 | ret = -EIO; | |
335 | /* convert to index and check */ | |
336 | index = (unsigned long) addr >> 2; | |
337 | if ((addr & 3) || index > PT_FPSCR | |
338 | || child->thread.regs == NULL) | |
339 | break; | |
340 | ||
341 | CHECK_FULL_REGS(child->thread.regs); | |
342 | if (index == PT_ORIG_R3) | |
343 | break; | |
344 | if (index < PT_FPR0) { | |
345 | ret = put_reg(child, index, data); | |
346 | } else { | |
347 | preempt_disable(); | |
348 | if (child->thread.regs->msr & MSR_FP) | |
349 | giveup_fpu(child); | |
350 | preempt_enable(); | |
351 | ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data; | |
352 | ret = 0; | |
353 | } | |
354 | break; | |
355 | } | |
356 | ||
357 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ | |
358 | case PTRACE_CONT: { /* restart after signal. */ | |
359 | ret = -EIO; | |
7ed20e1a | 360 | if (!valid_signal(data)) |
1da177e4 LT |
361 | break; |
362 | if (request == PTRACE_SYSCALL) { | |
363 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
364 | } else { | |
365 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
366 | } | |
367 | child->exit_code = data; | |
368 | /* make sure the single step bit is not set. */ | |
369 | clear_single_step(child); | |
370 | wake_up_process(child); | |
371 | ret = 0; | |
372 | break; | |
373 | } | |
374 | ||
375 | /* | |
376 | * make the child exit. Best I can do is send it a sigkill. | |
377 | * perhaps it should be put in the status that it wants to | |
378 | * exit. | |
379 | */ | |
380 | case PTRACE_KILL: { | |
381 | ret = 0; | |
382 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
383 | break; | |
384 | child->exit_code = SIGKILL; | |
385 | /* make sure the single step bit is not set. */ | |
386 | clear_single_step(child); | |
387 | wake_up_process(child); | |
388 | break; | |
389 | } | |
390 | ||
391 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ | |
392 | ret = -EIO; | |
7ed20e1a | 393 | if (!valid_signal(data)) |
1da177e4 LT |
394 | break; |
395 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
396 | set_single_step(child); | |
397 | child->exit_code = data; | |
398 | /* give it a chance to run. */ | |
399 | wake_up_process(child); | |
400 | ret = 0; | |
401 | break; | |
402 | } | |
403 | ||
404 | case PTRACE_DETACH: | |
405 | ret = ptrace_detach(child, data); | |
406 | break; | |
407 | ||
408 | #ifdef CONFIG_ALTIVEC | |
409 | case PTRACE_GETVRREGS: | |
410 | /* Get the child altivec register state. */ | |
411 | preempt_disable(); | |
412 | if (child->thread.regs->msr & MSR_VEC) | |
413 | giveup_altivec(child); | |
414 | preempt_enable(); | |
415 | ret = get_vrregs((unsigned long __user *)data, child); | |
416 | break; | |
417 | ||
418 | case PTRACE_SETVRREGS: | |
419 | /* Set the child altivec register state. */ | |
420 | /* this is to clear the MSR_VEC bit to force a reload | |
421 | * of register state from memory */ | |
422 | preempt_disable(); | |
423 | if (child->thread.regs->msr & MSR_VEC) | |
424 | giveup_altivec(child); | |
425 | preempt_enable(); | |
426 | ret = set_vrregs(child, (unsigned long __user *)data); | |
427 | break; | |
428 | #endif | |
429 | #ifdef CONFIG_SPE | |
430 | case PTRACE_GETEVRREGS: | |
431 | /* Get the child spe register state. */ | |
432 | if (child->thread.regs->msr & MSR_SPE) | |
433 | giveup_spe(child); | |
434 | ret = get_evrregs((unsigned long __user *)data, child); | |
435 | break; | |
436 | ||
437 | case PTRACE_SETEVRREGS: | |
438 | /* Set the child spe register state. */ | |
439 | /* this is to clear the MSR_SPE bit to force a reload | |
440 | * of register state from memory */ | |
441 | if (child->thread.regs->msr & MSR_SPE) | |
442 | giveup_spe(child); | |
443 | ret = set_evrregs(child, (unsigned long __user *)data); | |
444 | break; | |
445 | #endif | |
446 | ||
447 | default: | |
448 | ret = ptrace_request(child, request, addr, data); | |
449 | break; | |
450 | } | |
451 | out_tsk: | |
452 | put_task_struct(child); | |
453 | out: | |
454 | unlock_kernel(); | |
455 | return ret; | |
456 | } | |
457 | ||
458 | void do_syscall_trace(void) | |
459 | { | |
460 | if (!test_thread_flag(TIF_SYSCALL_TRACE) | |
461 | || !(current->ptrace & PT_PTRACED)) | |
462 | return; | |
463 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
464 | ? 0x80 : 0)); | |
465 | ||
466 | /* | |
467 | * this isn't the same as continuing with a signal, but it will do | |
468 | * for normal use. strace only continues with a signal if the | |
469 | * stopping signal is not SIGTRAP. -brl | |
470 | */ | |
471 | if (current->exit_code) { | |
472 | send_sig(current->exit_code, current, 1); | |
473 | current->exit_code = 0; | |
474 | } | |
475 | } |